Magneto-starter



J. R. M. S-TANFIELD.

MAGNETO STARTER.

APPLICATION FILED NOV- 23. 1920.

Patented Aug. 2, 1921.

UNlTED STATES PATENT OFFICE.

MAGNETO-STARTER.

Specification of Letters Patent.

Patented Aug. 2, 1921.

Application filed November 23, 1920. Serial No. 426,077.

To all whom it may concern Be it known that I, JOSEPH REGINALD MoNTAGun STANFIELD, subject of the King of England, residing at East Canal Wharf, Cardiff, ales, Great Britain, have invented certain new and useful Improvements in Magneto-Starters, of which the following is a specification.

This invention is for improvements in or relating to magneto-starters of the type wherein a driving-member is connected to the driven-member, which may be'the magneto-armature shaft, through the medium of a spring, and a pawl is provided to hold back the driven-member while the spring is loaded by turning the driving-member, which pawl is afterward automatically tripped so that the driven-member suddenly advances under the action of the spring and thus a quick turn is given to the magnetoarmature and the requisite spark is produced.

Magneto-starters of this type are usually provided with some means for yieldingly locking the driving and driven members together when in the position fornormal driving and one object of the present invention is to provide such a yielding locking-device which shall be subject to less wear than those at present on the market and which shall be of such construction that the cost of production may be decreased.

According to the present invention, a magneto-starter of the type described, is characterized by the means for yieldingly locking the driving and driven members together when in the position for normal driving, comprising a portion of spring which moves with one member (that is the driving ordriven member) and a pin which moves with the other member, the said spring portion being so shaped that it provides a butting face for this pin SlllllClGIlt to efiect the requisite looking but not sufficient to prevent the locking from being forced for starting purposes and being further so positioned that for starting purposes it is displaced by the pin in an approximately radial. direction relatively to the axis of rotation of the members, the resilience of the spring tending al- 7 ways to keep the said butting portion in the engaging position relatively to the pin.v

The invention further relates to the specific construction ofparts hereinafter fully described whose shape is such owing to the aforesaid form of locking-device that they.

can all be produced in quantity at a low price.

In the accompanying drawings which.

illustrate those parts of the magneto-starter whlch are necessary to the understanding of the invention:

Figure l is a central section through the said parts along the axis of rotation of the drlven member;

Fig. 2 is a section through the same parts on the line 22 of Fig. 1, and

Fig. 3 is a section through the same position of a modified form of the device,

The same letters indicate the same parts throughout the drawings.

The spindle of the magneto is indicated at A and mounted on this is a disk-like member B which is secured by its boss B to thej cone-shaped end of the spindle and locked in place by a nut B Mounted on the boss B is a dlshed member whose central portion C is surrounded by a springD one end of which is fixed to the said central portion at D The disk B carries a pin B which projects into the dished member C and is en gaged with the upper end of the spring D.

The dished member 0 also carries a pin C which lies in the path of the pin 13 and the" spring D hason its outer end a projection D which butts against the opposite side of the pin C to that on which the pin B is situated. The part of the spring which carries the projection D tends to move outward and is in fact thrust inward by the pin 6 so that the butting portion D is always kept against the pin 0 when the parts are in the position shown in Fig. 2' In the edge of the disk B, notches B are provided and a pawl E pivoted at E to a fixed part of the mechanism not shown in the drawings is so placed as to engage either of the notches when brought to register with it. Projecte ing laterally from the pawl E is a pin E and on the outer periphery of thedished member C are two cams C while lie infthe path of the pin E The operation of this device is as fol-- lows As the engine is cranked around, the member C is advanced in the direction of the arrow, Fig. 2, but the member I3 and there-- fore the magneto-shaft A. is held against rotation by the pawl E. Y WVhen the member 0 has been turned through an angle of 90 from the position shown in the drawing, one of the cams C comes into contact with the pin E and thrusts the pawl out of engage ment. Thespring' D has been loaded by the advance of the member G, and consequently the member B will advance rapidly under the action of the spring until the pin, B strikes against the pin 0 This rapid advancemovement of the member B gives-the requisite partial rotation to the armature spindle A to produce the necessary spark. Meansnot shown in the drawing are provided for throwing the pawl E out of action as soon as the englne isstarted, and the two parts 13 and Garethen yieldingly locked together for normal driving by the end'of the spring D, which engages one side of the pin 13 as shown in the drawing and which, by means of the projection D engages the opposite side of the pin C The projection D is of a yielding-character as will be readily understood, so that it does not interfere with the movement of thepin C away from the pin B for starting purposes as it is then forcibly thrust aside, but itholds the pin G against the pin B witlrsuilicientfirmness for normal driving. The projection D has a further use, namely that it decreases the impact of the pin B against the the member B is tripped.

In Fig; 3, the parts B and C with their driving spring and yielding loci: are the same as those shown in Figs. 1 and 2,but.a

furtherloclris provided by means of a separatepiece ofsprin 1?" which is secured in the dished member 7 directed butting projection F This projection cocperates with a pin G on the member. B so that "a dual loclr is provided. Ob- Viously'the spring F with its projection F could be arranged on the member C to co operate. with thepin B instead of a separat'epin G provided the end of the spring Dis so arranged on the pin B as not to be displaced by the operation of the projection F and the pin C be so shaped as not 'tofoul the spring F With this dual lock,

the operation is thesame as has been described with the single lock, that is, the projections D? and F are forced when the 7 member C is moved in the direction of the arrow for starting, and when tripping takes placeigthe projections both act to cushion the art p It will be seen that in this apparatus, the parts are all readily constructed as there is no special shaping required in the dished member C which can be machined out in one operation, or can be stamped; the cams C thereon can be formed by bulging out the sides if stamping is the process employed. Themember B also is a plain disk and hasno parts subject to any particular wear so that j r it can be made in mild steel, with the result pin 0 when 3: and has aninwardly that a magneto-starter of few parts requiring little machining is produced.

What Iclaim as'my invention and desire to secure by Letters Patent is 1. In yielding locking means for the driving and driven members of a magnetostarter the combination with one of the aforesaid movable members of a portion of spring whlch moves with sa1d member, and

a pin which moves with the other member,

the said spring portion being so shaped-that it provides a butting face for the pin sufficient to effect the required locking of the one member relatively to the other but not sufiicient to prevent such locking from being forced for starting purposes and said spring portion further being so positioned that for starting purposes it is displacedby the said ber, of a spring secured atone end thereto and having its other end curved to lie ap p-roximately along an arc struck from the axis of rotation of said first member, the other. end, hereinafter called the driving end, being engaged with a pin on the fellow member, hereinafter. called the second mem ber, andprovided with apart which pro ,jects approximately radially outward from the axis of rotation of the members and between the aforesaid pin and thedriving end of the spring to engage a second pin carried by the first member, said projecting portion constituting a butting face for the pin on the second member sufficient to e'fiect the required locking of the one member relatively to the other, but not suflicientto prevent such' locking from being forced for starting purposes," said projection being near enough to the pin on the second member so that the pin on the first member shall be held close against the pinon' the second member when engaged by the buttingportion, substantially as set forth. i

3. In yieldinglocking means for the driving and driven members of a magnetostarter the combination with one of theaforesaid movable members of a portion of spring which moves with said member, and a pin which moves with the other member, the said spring portionbein'g so shaped that it provides a butting face for the pin sufii cient to effect the required lockingof the one.

forced for starting'pnrposes and said spring portion further being so positioned that for starting purposes it is displaced by the said pin in an approximately radial direction relatively to the axis of rotation of the members, the resiliency of the spring tending always to keep the said butting portion in the engaging position relatively to the pin,

one of the movable members being dished to receive the spring and cooperating pins, said dished portion further being closed in 10 by the cooperating member, substantially as set forth.

In testimony whereof I affix my signature.

JOSEPH REGINALD MONTAGUE STANFIELD. 

